Fix GeoSeries.to_json

geopandas/geoseries.py

@@ -6,7 +6,7 @@ from pandas import Series, DataFrame
 from pandas.core.indexing import _NDFrameIndexer
 from pandas.util.decorators import cache_readonly
 import pyproj
-from shapely.geometry import box, shape, Polygon, Point
+from shapely.geometry import box, mapping, shape, Polygon, Point
 from shapely.geometry.collection import GeometryCollection
 from shapely.geometry.base import BaseGeometry
 from shapely.ops import transform
@@ -273,6 +273,23 @@ class GeoSeries(GeoPandasBase, Series):
         result._invalidate_sindex()
         return result
 
+    def to_json(self, **kwargs):
+        """
+        """
+        def geometry_handler(x):
+            if isinstance(x, BaseGeometry):
+                return {
+                        'type': 'Feature',
+                        'properties': {},
+                        'geometry': mapping(x)
+                    }
+            else:
+                return x
+        kwargs.setdefault('default_handler',geometry_handler)
+        kwargs.setdefault('orient','records')
+        features = super(GeoSeries,self).to_json(**kwargs)
+        return '{"type":"FeatureCollection","features":%s}' % features
+
     #
     # Implement standard operators for GeoSeries
     #

tests/test_geoseries.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import os
+import json
 import shutil
 import tempfile
 import numpy as np
@@ -116,6 +117,13 @@ class TestSeries(unittest.TestCase):
         self.assertTrue(all(self.g3.geom_equals(s)))
         # TODO: compare crs
 
+    def test_to_json(self):
+        """Test whether GeoSeries.to_json works and returns an actual json file."""
+        s = GeoSeries.from_file(tempfilename)
+        json_str = s.to_json()
+        json_dict = json.loads(json_str)
+        # TODO : verify the output is a valid GeoJSON.
+
     def test_representative_point(self):
         self.assertTrue(np.alltrue(self.g1.contains(self.g1.representative_point())))
         self.assertTrue(np.alltrue(self.g2.contains(self.g2.representative_point())))